Evaluation of non-invasive bioforensic techniques for determining the age of hot-iron brand burn scars in cattle

Hot-iron branding is a traditional form of permanent cattle identification in the United States. There is a need for science-based determination of cattle brand age. Near infrared reflectance spectroscopy (NIRS) has been used to obtain information about animal tissues and healing processes. Height-width allometry and NIRS were applied to hot-iron cattle brand scars to determine if either or both of these methods can be used to non-invasively establish the interval sincethe application of hot-iron cattle brands. Length and width of a brand routinely applied to calves (~30-60 d old) were established and then the same measurements were recorded on 378 calfhood branded cattle of known age ranging from 0.5 to > 6.5 yr-of-age. Brand width and height increased over the original measurements by > 100% between calfhood application and 2.5 yr-of-age (P 6.5 yr, however, both width and height were (P < 0.05) greater at maturity than at weaning. Near infrared spectra were collected from a) branded skin b) non-clipped (hair), non-branded skin, and c) hair clipped, nonbranded skin on Bos taurus cross calves. Individual trial calibrations yielded high R2 and low SE of calibration values as well as similar cross validation performance (P < 0.001). Numerically lower but still strong performance (P < 0.001) resulted from combined data set calibrations. Cross-trial prediction of brand age was unsuccessful. One single year calibration underpredicted (P < 0.001) brand age of an independent validation set by 2.83 d, and another single year calibration underpredicted (P < 0.001) the same validation set by 9.91 d. When combined, these two datasets resulted in a calibration that overpredicted brand age in the validation set by 6.9 d (P < 0.02). Discriminant analyses for identification of skin surface type yielded success rates of 90% for branded, 99% for non-clipped, non-branded, and 96% for clipped, non-branded (P < 0.01). Discriminant analyses were also performed on samples grouped into a) less than 33 d, b) 141-153 d, and c) 169 d categories. All group membership identifications were successful at greater than 90% (P < 0.01). Preliminary results indicate that brand size could be used to indicate brand age and that NIRS can predict brand age as well as discriminate between broad brand age groups in cattle. More work will need to be done before these techniques can be used in real-world forensic applications. © The Author(s) 2021. Published by Oxford University Press on behalf of the American Society of Animal Science.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Old School and High Tech: A Comparison of Methods to Quantify Ashe Juniper Biomass as Fuel or Forage

Ashe juniper invasion is a widespread issue on Texas and Oklahoma rangelands. Increased densities of Ashe juniper trees increase the risk of wildfire and decrease herbaceous forage production. Browsing animals, such as goats, are one tool that can be used to effectively reduce juniper fuel. In order to estimate the available biomass, allometric measurements were compared against three-dimensional Light Detection and Ranging (LiDAR) scans of whole juniper plants. Accurate measurements of standing juniper browse and fuel load can be vital information for decision support of grazing management and wildland fire mitigation, especially in the ever-growing wildland-urban interface.The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information

Near infrared spectroscopy of faeces to evaluate the nutrition and physiology of herbivores

Near infrared (NIR) spectroscopy, usually in reflectance mode, has been applied to the analysis of faeces to measure the concentrations of constituents such as total N, fibre, tannins and delta C-13. In addition, an unusual and exciting application of faecal NIR [F.NIR] analyses is to directly predict attributes of the diet of herbivores such as crude protein and fibre contents, proportions of plant species and morphological components, diet digestibility and voluntary DM intake. This is an unusual application of NIR spectroscopy insofar as the spectral measurements are made, not on the material of interest [i.e. the diet), but on a derived material (i.e. faeces). Predictions of diet attributes from faecal spectra clearly depend on there being sufficient NIR spectral information in the diet residues present in faeces to describe the diet, although endogenous components of faeces such as undigested debris of micro-organisms from the rumen and Large intestine and secretions into the gastrointestinal tract wilt also contribute spectral information. Spectra of forage and of faeces derived from the forage are generally similar and the observed differences are principally in the spectral regions associated with constituents of forages known to be of low, or of high, digestibility. Some diet components (for example, ureal which are likely to be entirely digested apparently cannot be predicted from faecal NIR spectra because they cannot contribute to faecal spectra except through modifying the microbial and endogenous components. The errors and robustness of F.NIR calibrations to predict the crude protein concentration and digestibility of the diet of herbivores are generally comparable with those to directly predict the same attributes in forage from NIR spectra of the forage. Some attributes of the animal, such as species, gender, pregnancy status and parasite burden have been successfully discriminated into classes based on their faecal NIR spectra. Such discrimination was likely associated with differences in the diet selected and/or differences in the metabolites excreted in the faeces. NIR spectroscopy of faeces has usually involved scanning dried and ground samples in monochromators in the 400-2500nm or 1100-2500nm ranges. Results satisfactory for the purpose have also been reported for dried and ground faeces scanned using a diode array instrument in the 800-1700nm range and for wet faeces and slurries of excreta scanned with monochromators. Chemometric analysis of faecal spectra has generally used the approaches established for forage analysis. The capacity to predict many attributes of the diet, and some aspects of animal physiology, from NIR spectra of faeces is particularly useful to study the quality and quantity of the diet selected by both domestic and feral grazing herbivores and to enhance production and management of both herbivores and their grazing environment